Ukraine marks Chernobyl anniversary

A boy points to his grandmother's portrait in the Chernobyl victims' monument in Slavutich.

Sergei Supinsky: AFP

Sombre ceremonies in Ukraine have marked the 25th anniversary of the Chernobyl nuclear disaster.

In the early hours of April 26, 1986, workers at the Chernobyl atomic power station were carrying out a test on a reactor when operating errors and design flaws sparked successive explosions.

The explosion released huge amounts of radiation into the atmosphere, creating an apocalyptic scene in the surrounding area and sending a fallout plume across Belarus and Russia and into western Europe.

Two workers were killed by the explosion and 28 other rescuers and staff died of radiation exposure in the next months. Tens of thousands needed to be evacuated and fears remain of the scale of damage to people's health.

Commemorations in Ukrainian capital Kiev started in the middle of the night, with hundreds of workers who were sent to clean up the disaster - known as liquidators - gathering at a church memorial.

Later today the presidents of Ukraine and Russia are expected to be joined by the president of Belarus on a visit to the stricken plant, which is still surrounded by a 30-kilometre exclusion zone.

The anniversary has gained an eerily contemporary resonance after the earthquake in Japan which damaged reactors at the Fukushima power plant and prompted leaks of radiation.

Japan has placed the disaster on the maximum seven on an international scale of atomic crises, the same level as Chernobyl, and the troubles at Fukushima have prompted many questions about whether atomic power is too great a risk.